Spur Gear Housing Flow Deflection for Thermal Load Control
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Solution Overview
Problem
Existing spur gears experience uneven heating and strong, locally limited thermal loads on the outer housing due to the direct flow of hot lubricant-air mixtures from axial and radial openings, which is not effectively managed by current designs.
Innovation Solution
The spur gear design incorporates a shielding element between the inner and outer housings to deflect lubricant flows from axial and radial openings, preventing direct contact with the outer housing and distributing the flow over a larger area, while using a coolant injection device to further cool and redirect the lubricant-air mixture.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If axial and radial openings are provided in the inner housing for lubricant flow, then heat dissipation from gear teeth is improved, but uneven heating and strong local thermal loads on the outer housing occur
Solution Approach 1:
A shielding element is introduced as an intermediary component between the inner housing and outer housing. This shielding element intercepts the hot lubricant-air mixture exiting the axial and radial openings, preventing direct contact with the outer housing. The shielding element redirects the flow through drainage channels, distributing thermal load more evenly while maintaining effective heat dissipation from the gear teeth.
Solution Approach 2:
The shielding element extends in the radial direction between the inner and outer housings, creating a new spatial dimension for flow management. By positioning the shielding element radially outward from the axial openings and radially inward from the outer housing, the patent adds a radial layer to the traditional axial-radial flow path, enabling intermediate flow redirection and thermal load distribution.
2Loss of energy
If the inner housing tightly encloses the spur gears, then ventilation and flow losses are reduced, but heat management becomes more challenging
Solution Approach 1:
The housing system is segmented into multiple functional zones: the inner housing for tight gear enclosure and initial heat dissipation, the shielding element for intermediate flow management, and the outer housing for final heat dissipation and structural support. This segmentation allows each component to perform its specific function optimally while working together for overall heat management.
Solution Approach 2:
The shielding element serves as a mediator between the tightly enclosed inner housing and the outer housing. It receives hot lubricant-air mixture from the inner housing, prevents direct impact on the outer housing, and channels the flow through drainage channels, thereby facilitating heat transfer from the enclosed gear system to the external environment.
3Object-affected harmful factors
If shielding elements are added to deflect lubricant flows, then thermal loads on the outer housing are reduced, but device complexity increases
Solution Approach 1:
The shielding element is merged with the drainage channel system, combining the flow deflection function and the drainage function into a single integrated component. This merging reduces the number of separate parts needed while achieving both thermal load reduction and effective lubricant drainage.
Solution Approach 2:
The shielding element performs multiple functions simultaneously: it shields the outer housing from direct thermal exposure, redirects lubricant flow through drainage channels, and maintains the pressure differential needed for effective heat dissipation. This multi-functionality reduces overall system complexity despite adding a component.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This design effectively reduces thermal loads on the outer housing, maintaining the advantages of close encapsulation and heat dissipation while minimizing uneven heating, thus enhancing the durability and efficiency of the spur gear system.
Implementation Method 1
a coolant injection device is provided in the region of the axial openings and/or radial openings and/or on the shielding elements, with which a coolant can be introduced into the lubricant flowing out of the axial opening or radial opening
Implementation Method 2
the shielding element is arranged in such a way or at such a distance from the respectively covered axial opening or radial opening that lubricant flowing out of the axial opening or radial opening is deflected outside the inner housing by the shielding element
Data Source
Figure 1a~1d
Figure 2~3
Figure 4~5
AI summary
The invention relates to a spur gear transmission comprising at least two toothed spur gears which are each mounted on a shaft and the gear teeth of which mesh with one another in pairs; wherein the spur gears each have a radially outer periphery and two axial sides facing away from one another, and the spur gears are enclosed by an inner housing over most of their radially outer periphery and over most of their axial sides facing away from one another, which inner housing in turn is completely enclosed by an outer housing positioned separately thereto; wherein lubricant is applied to the spur gears in the region of their gear teeth and the inner housing has axial openings which face one or both axial sides of at least one spur gear and/or radial openings which face the radially outer periphery of at least one spur gear and through which the lubricant can flow at least indirectly out of the inner housing. The spur gear transmission according to the invention is characterised in that at least one, several or all axial openings and/or radial openings are covered by a shielding element located between the inner housing and the outer housing, the shielding element being positioned in such a way or at such a distance from the covered axial opening or radial opening that lubricant flowing out of the axial opening or radial opening is deflected by the shielding element outside the inner housing; and/or at least one, several or all axial openings and/or radial openings are assigned a coolant injection with which coolant is injected into the lubricant flowing out of the axial opening or radial opening in such a way that the lubricant flowing out of the axial opening or radial opening is deflected by the coolant outside the inner housing.